Explain EXPLAIN SYNTAX (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 1)
    ExpressionList (children 1)
     Function CAST (children 1)
      ExpressionList (children 2)
       Function arrayElement (children 1)
        ExpressionList (children 2)
         Function CAST (children 1)
          ExpressionList (children 2)
           Literal \'[3,4,5]\'
           Literal \'Array(Int64)\'
         Literal UInt64_2
       Literal \'Int8\'
